Crucible or converter



Feb. 14, 1967 P. PUXKANDL 3,304,075

CRUCIBLE OR CONVERTER Filed Dec. 10, 1963 2 Sheets-Sheet 1 INVENTOR. PETER PUXKANDL.

m.%.,awm W ,Lu', ATTORNEYS.

Feb. 14, 1967 P. PUXKANDL CRUCIBLE OR CONVERTER 2 Sheets-Sheet 2 Filed Dec. 10, 1963 INVENTOR. PETER PUXKANDL BY ,ZA'A ATTORNEYS United States Patent 3,304,075 CRUCIBLE OR CONVERTER Peter Puxkandl, Linz, Austria, assignor t0 Vereinigte Gsterreichische Eisenund Stahlwerke Aktiengesellschaft, Linz, Austria, a company of Austria Filed Dec. 10, 1963, Ser. No. 329,452 Claims priority, application Austria, Dec. 14, 1962, A 9,800/62 7 Claims. (Cl. 266--36) This invention relates to a crucible or converter for carrying out top-blowing processes. Known crucibles comprise a cylindrical or pear-shaped vessel provided with a refractory lining. The tilting bearing of such crucibles is mostly effected by carrying or trunnion rings having trunnions secured thereto, or else-in the case of crucibles without a trunnion ring-the trunnions are secured directly to the crucible wall. As the crucible wall is exposed to considerable thermal stresses, it is necessary to cool the trunnions and the carrying ring.

In the course of development of the top-blowing processes there has been an increasing trend towards larger crucible sizes. This entails the problem that the crucible mouth is subjected to undue stresses and that its durability is no longer sufiicient. Thermal stresses caused by heat from the inside of the crucible, =by reflection from the flue, by the slag slopping, by the radiation of the flame bursting through the crucible mouth, and mechanical stresses caused by the formation of skulls which have to be removed mechanically (stroke or shock) in large crucibles may reach such a degree that the upper parts of the cruelbles are subjected to considerable deformations and damages, notwithstanding the good durability of the crucible shell and the lining in other parts of the crucible. It has been proposed to provide for the upper part of crucibles to be exchangeable and to replace the upper part earlier than the rest of the lining. Of course, the interruption of a converter cycle for this purpose results in a heavy loss and additional expenses.

It is the object of the invention to avoid the mentioned disadvantages and difficulties. The invention resides in that a protective ring supplied with a coolant is arranged to surround the mouth of the crucible or a part of the crucible mouth and mounted in such manner that an air gap is provided between the crucible wall in the region of the crucible mouth and the cooled wall area'of the protective ring.

The double-walled protective ring advantageously has a hook-like profile, the flange extending radially inwardly forming a part of the end face of the crucible mouth by being in alignment with the end faces of the lining bricks of the crucible mouth, and the other flange being adjusted to the inclination of the crucible wall in the upper part of the crucible.

The part of the protective ring extending radially inwardly may comprise at several places, e.g. in the region of the slag hole, a wear-resisting material, preferably a spheroidal cast-iron plate.

In order to avoid thermal deformations between the heated and the cooled parts, the invention further proposes to mount that part of the protective ring which surrounds the crucible wall in spaced relation on support members arranged on the crucible wall, e.g. small consoles welded to the crucible wall, which is preferably effected by means of screws and oblong holes or slots which enable a perfect fit but avoid a jam.

The protective ring may consist of one or several parts and can be easily replaced.

The arrangement according to the invention ensures an excellent durability of the upper part of a top-blowing crucible; it provides for a reliable protection from thermal Patented Feb. 14, 1967 influences from above and from the outside; the circulation of air along the walls of the crucible is not impeded, and it is ensured that differences in heat expansion cannot cause damages anywhere.

In the drawing an exemplary embodiment of the invention is explained more fully. FIG. 1 is a lateral view of the crucible. FIG. 2 is a vertical sectional view perpendicularly to the plane of drawing of FIG. 1, and FIG. 3 is a vertical sectional view in the plane of drawing of FIG. 1.

The crucible comprises the crucible shell 1 and the refractory lining 2. The upper edge of the crucible shell 1 carries a narrow rim 3 extending radially inwardly. Consoles 4 are welded at peripherally spaced places onto the crucible-wall and serve as support members for the protective ring 5. The protective ring itself has a hook-like profile, the flange 6 extending radially inwardly and forming a part of the end face of the crucible mouth by being in alignment with the end face 8 of the lining bricks of the mouth, whereas the other flange 7 is adjusted to the inclination of the crucible wall 1 in the upper part of the crucible. The two parts of the protective ring 6 and 7 are double-walled so as to include cavities 9 and 10 which communicate with each other so as to provide for a flow of a coolant, such as water; numeral 11 denotes a partition wall.

Between the cooled walls of the ring and the outside wall of the crucible shell 1 and 3, respectively, there is an air gap 12 left free, as the parts 6 and 7 of the ring are propped against the crucible shell 1 and the part 3 by means of supporting bolts 13 which serve as spacers. The mounting of the ring on the consoles 4 is preferably eifected by means of screws and oblong holes, so that slight movements are possible at the places of fastening.

As is evident from FIG. 3, the part 6 of the protective ring which extends radially inwardly may consist of solid material 14 at predetermined places of the periphery, which are exposed to particularly heavy stresses, e.g. in the region of the slag hole or of the tapping hole. Thus, this part of the ring is not double-walled, but has a wearing plate welded therein which has the same thickness as the remaining double-walled part 6 (including the gap 12 otherwise formed) and may advantageously consist of spheroidal cast-iron. Suitably such wear plates 14 are provided at two opposite places of the ring, as is evident from FIG. 1.

The protective ring according to the invention may consist of one or several parts, depending on the size of the crucible. Two-part rings have proved particularly satisfactory.

The supply and discharge of the coolant may be effected in a manner as is known for the cooling of the trunnions or the trunnion ring, and the conduits may be connected to the cooling system of the said parts. In FIG. 1 the supply conduits are designated by 15, and the discharge conduits are designated by 16, the said conduits being secured to the outside wall of the crucible shell 1. Alternatively they may. be irnbedded in the permanent lining of the crucible.

What I claim is:

1. A crucible for carrying out top-blowing processes and having a Wall and a mouth, comprising a hollow protective ring to be supplied with a coolant fixed to and surrounding at least part of the crucible mouth and means supporting said ring in spaced relation to said crucible wall and said mouth of the crucible to provide an air gap betweensaid ring and said wall and said mouth.

2. A crucible for carrying out top-blowing processes, comprising a crucible body having a tapered mouth part, a double walled protective ring having a hook-like profile arranged to surround at least part of the crucible mouth,

ring, the one flange of said protective ring which extends radially inwardly forming a part of the end face of the crucible mouth and the other flange surrounding said mouth part in spaced relation and being adjusted to the inclination of said mouth part of the crucible.

3. A crucible as set forth in claim 2, wherein the crucible body including the mouth part is lined with refractory bricks and said flange extending radially inwardly is in alignment With the end faces of the bricks of said mouth part.

4. A crucible as set forth in claim 2, wherein the flange of the protective ring which extends radially inwardly comprises a wear-resisting material.

5. A crucible as set forth in claim 2, wherein the flange of the protective ring which surrounds the crucible mouth part in spaced relation is mounted on support members arranged on the crucible body.

6. A crucible as set forth in claim 2, wherein the flange of the protective ring which surrounds the crucible :tective ring consists of two par-ts, each part being connected to a separate cooling system having supply and discharge conduits, a partition member being arranged in each of said parts to provide for a circulation of the coolant in each of said parts of the protective ring. 7

References Cited by the Examiner UNITED STATES PATENTS 3,043,578 7/1962 Cohn 26641 3,195,875 7/1965 Mummert 266-36 3,215,425 11/1965 Vogt 266- JOHN F. CAMPBELL, Primary Examiner.

J. M. ROMANCHIK, Assistant Examiner. 

1. A CRUCIBLE FOR CARRYING OUT TOP-BLOWING PROCESSES AND HAVING A WALL AND A MOUTH, COMPRISING A HOLLOW PROTECTIVE RING TO BE SUPPLIED WITH A COOLANT FIXED TO AND SURROUNDING AT LEAST PART OF THE CRUCIBLE MOUTH AND MEANS SUPPORTING SAID RING IN SPACED RELATION TO SAID CRUCIBLE WALL AND SAID MOUTH OF THE CRUCIBLE TO PROVIDE AN AIR GAP BETWEEN SAID RING AND SAID WALL AND SAID MOUTH. 